A pressure switch is a type of switch in which the switching action is triggered by pressure in the surrounding environment. Pressure switches have been proposed for use in various kinds of electro-mechanical devices. A typical pressure switch has a diaphragm that is impinged upon by media, such as air under pressure, and upon reaching a particular pressure the diaphragm causes the switch contacts of the pressure switch to be actuated from the off-to-on or on-to-off position by snap action, creating a binary type output.
However, in many instances, such as in modern control systems, it is desirable to utilize a switch that provides an analog output such that the output varies according to applied pressure or vacuum. Conventional pressure switches do not meet this need because snap action actuation of the conventional switches causes a binary signal to be output instead of an analog signal. For example, snap action actuation from the off-to-on or on-to-off position does not allow for an output that is approximately proportional to applied pressure or vacuum.